There has been conventionally continuous issuance of a multitude of alarms from field equipment, a distributed control system (DCS), and so forth, whereby a screen for monitoring alarm messages is filled with alarm messages, to be rendered in a so-called alarm flood state, thereby contributing to oversight of an important alarm or erroneous judgment by a plant operator. To that end, it is required to suppress the notification of alarms to the operator in response to states of the plant and operation situations.
Consequently, even if a multitude of alarms are issued, there has been executed an alarm management wherein only necessary alarms are notified to the operator at the optimum time by making a choice of information.
There is a dynamic alarm suppression method as one of alarm suppression methods. If an alarm is issued in a plant due to the occurrence of anomalies at some spots in the plant, it secondarily triggers anomalies at other spots in the plant, causing the issuance of a tailgate alarm. For example, if flow anomalies occur at upstream, it causes flow anomalies to occur at downstream.
In such a case, it is possible to ease strain on the operator by notifying only a triggered first alarm to the operator and suppressing a secondary tailgate alarm so as to be eliminated from a watch list.
FIG. 6 is a view for explaining conventional alarm suppression.
A DCS controller 1a, a safety instrumented system (SIS) controller 1b and a PLC controller 1c are connected to a control bus 2, respectively. A DCS engineering station 3a, an SIS engineering station 3b and a PLC engineering station 3c, each provided for a plant engineer to execute engineering for every DCS controller 1a, SIS controller 1b and PLC controller 1c, are connected to the control bus 2, respectively. Situations of the plant are monitored by a plant operator in a monitoring station 4 connected to the control bus 2.
The conventional suppression of a tailgate alarm (hereinafter referred to as tailgate alarm suppression) is executed as detection logics for every DCS controller 1a, SIS controller 1b and PLC controller 1c. For example, in case the tailgate alarm of the field equipment connected to the DCS controller 1a is to be suppressed, the plant engineer executes engineering relative to the DCS controller 1a through the DCS engineering station 3a, or constructs logics so that the tailgate alarm, that is secondarily issued while triggered by the issuance of some alarm, is not notified.
[Patent Document 1] JP2003-186536A
According to the conventional tailgate alarm suppression, it is necessary to construct logics for executing suppression for every kind of controller and for every device, leading to difficulty in engineering.
Further, if there occurs errors in constructed logics, there is the possibility of exerting an influence upon the operation of the controllers.
Still further, since the logics are constructed for executing the tailgate alarm suppression for every controller, there was a problem in that an alarm, that is issued while extended over the controllers, can not be suppressed.